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Hello there, you beautiful people.

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Now, the terminal is a very powerful tool that is designed to allow you to issue what are known as

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commands to your computer.

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Now, the idea is that the computer will obey these commands, we hope, and make stuff happen as a

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result.

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Now, in this video, you're going to learn how to issue your first commands, which is very exciting.

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But as an aside, this course is structured so that each section of the course has its own cheat sheet

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that you can grab at the end of the section.

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So don't worry about memorizing all the commands or rushing down to take notes.

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Just try it.

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The commands that I show you in your own virtual machine or on your own computer, and rest assured

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that everything is all jotted down for you in the cheat sheets that you can get at the end of each section.

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So that's awesome, right?

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So by the end of this video, you will have ran a bunch of Linux commands and you'll start to see a

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pattern emerging in how Linux commands work.

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So this is going to be a very important lecture.

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It's going to give you that foundation.

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It's going to help you understand what everything is all about.

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So let's go ahead and jump into it.

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Okay.

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So the first thing we're going to want to do is to open up our terminal.

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Now, as a quick challenge, let's see if you can remember how to do that.

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Go ahead and see if within about 5 seconds or so you can open up the terminal.

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You can do it using either graphical methods or if you're feeling particularly pro already, use the

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keyboard shortcut you learned in the last video.

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So you've got 5 seconds.

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Give it a go.

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Did you get it?

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Well, if so, well done.

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You're learning already.

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Now I'm going to open up the terminal using the keyboard shortcut, which is control, alt and T, and

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there's the terminal popped up.

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Now I'm going to do it like that for most of the time from now on.

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So don't be confused.

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If you see terminal windows popping up all over the place as we go through the course, I'm just using

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the keyboard shortcut, but to make the text a bit easier to read on the recording, I'm just going

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to hit view and click zoom in.

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We'll make the font just that much larger.

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So that should make it a bit easier for you to read when I type stuff.

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But now that terminal windows open, let's run a fun command called Echo.

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Now the Echo Command just prints out what you give it as an input.

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So type with me the following command.

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We're going to type Echo, then press space and we're going to type the word hello.

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Now when I press enter, I'm going to say to the computer, okay, actually run this command and when

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I press enter we see hello, come out of the computer.

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It's that's pretty cool.

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Let's try that again.

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Okay.

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We're going to say echo then type echo.

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With a load of ohs.

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Okay, then I'm going to press enter and what comes back is echo.

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How awesome is that?

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It's just like a cave.

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So let's try now with another command called Cal.

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So that's Echo.

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Let's try with another command called Cal.

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And Cal is going to show up a calendar on the screen.

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So if we type Cal just like that and press enter, you can see that we get a calendar for the current

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months, for the current month with the with today's date also highlighted.

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And now I'm doing this in October 2017.

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When you're watching this and doing it yourself, it may be a very different month, but you get the

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point.

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You type cal.

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The default behavior is that you get the current month with the current day highlighted, but that's

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just the default behavior of the Cal command.

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Now, what makes Linux Command interesting is how you don't have to stick with the default behavior.

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You can actually customize the behavior of commands to exactly what you want them to do.

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So, for example, what if I wanted the calendar not just for the current month but for the current

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year?

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But what I could do, first of all, I could type Cal then 2017 and I could press enter and it's going

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to give me the entire calendar for 2017 and also it's going to highlight the current date.

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So that's pretty cool with very little typing.

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We've got a lot more result out of that, right?

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But you can also give it something, give each command something called an option.

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Now an option is something that allows you to customize the behavior of the command.

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So I could type Cal and instead of typing 2017, I could just type dash y.

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Now this would give the Cal command the Y option.

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Now if I press enter, we also get the calendar for 2017.

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So you can see here Cal Dash y gave us the calendar for 2017, again highlighted with the current date.

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So you've just seen two ways that you can customize a commands behavior, you can give it input and

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you can give it options.

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And we're going to be going into a lot more detail about the difference between the two and how they

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work.

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But you may be curious at the moment as to what other ways you can customize commands, but I'm going

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to save that goodness until later at the minute.

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I just want to give you a little bit of a bit of an overview of some different commands that you can

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use on Linux so you can get comfortable with the typing and pressing enter and seeing results come back

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up on the screen.

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So let's move on and take a look at another one.

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For example, you can see today's date using the date command.

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So if we type, date and press enter, we see that we get today's date and time and time zone and year

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pop up.

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Okay, so that's pretty cool.

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It's quite a useful command, but at the moment you can see that we've got quite a lot of text and our

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terminal things are starting to get a bit messy.

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We can clean that up a bit as well.

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So to do that we can use the clear command.

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If we type clear and press enter, it's like we just cleaned up our workspace and there we are.

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We've removed all the text from the screen now because the clear command is used so often, there's

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a key, there's a keyboard shortcut for it.

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So if I just type echo and then put blah blah blah, you can see we've got some text come out on the

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screen, the computer said blah, blah, blah.

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But we can also use a keyboard shortcut to clear the screen.

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And that keyboard shortcut is you press control.

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And the letter L now we are, we've clear the screen.

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Now that's the way that I'm going to be doing it, because it's a lot faster and it's a lot easier than

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typing out the clear command every time.

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But you feel free.

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You do.

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You just understand that if the if the terminal is all of a sudden having all its text vanish, that's

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what I've done.

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I've just cleared the screen now.

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We've entered quite a few commands already.

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So what if you wanted to enter a command that you've entered previously without having to, you know,

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type it out again?

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Maybe it was a particularly long command.

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We don't know.

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But what you can do is you can hit the up arrow key on your keyboard.

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So if I press the up arrow key, we see echo, blah, blah, blah, tops, back up.

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If I press up again, it's going to go clear.

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And again we see date, again we see Cal and so on.

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Okay, so you can keep pressing up and cycling backwards through the commands that you've already run,

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which is very, very useful.

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But you can also look at your whole command history using what's called the history command.

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So if you type history and press enter, we can see all of our previous commands with the line number

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associated with them.

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For example, we can see the line number for our echo command, which is the number one.

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Let's say let's there we are.

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The line number is number one.

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And to run that what you could do instead of having to cycle all the way back up to number one like

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that, what I could do is I could type the exclamation mark and then one so exclamation mark on one

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and you can see that we've run echo.

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Hello.

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Okay, so let's, let's have a look again.

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Let's have a look at our history again.

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We see now let's say we want to run echo, blah, blah, blah.

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The line number for that is eight, right?

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So if I press the exclamation mark and press eight and then press enter, we see, we get echo, blah,

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blah, blah.

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So you can see that that's a bit of a shortcut to save you going back through potentially hundreds of

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commands that you've run.

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And, you know, you can you can run them a bit easier like that.

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And if you want to run.

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The most recent command that you've done.

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You can just press exclamation mark, exclamation mark.

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And again, we see blah, blah, blah has run again.

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Now this history file can get quite long.

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So if you want to clear the history or it's kind of a two step process, you can type history and give

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it the C option, then add a semicolon, then type history.

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And give it the the W option.

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So what that does is it clears the history and then actually writes those changes and makes them permanent.

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So when we do that and I've just cleared the screen and we look at history, we can see that all we've

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got is just a history command that we literally entered.

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So that's something for reference for you.

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It's not particularly important, but you've got it in this video if you want to refer back to it.

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Okay.

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Now, finally, let's say we want to close the terminal.

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Okay.

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Well, to do that, we could, of course, click the X button at the top right over here.

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But you can also type the exit command and make yourself just look that much more pro.

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Okay.

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So if we press exit, we can see that the terminal has now closed.

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And also you could of course use the control DX keyboard shortcuts if I press control and D we can see

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that the terminal is also closed as well, like I showed you in the last video.

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And that allows you to type commands, operate the terminal and also close it without ever having to

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take your hands off the keyboard.

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So there you have it.

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You've jumped right in and have now ran a whole bunch of Linux commands inside the terminal.

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So well done.

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You've got your feet wet and we're moving.

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As I mentioned to you, you can get a cheat sheet which covers all of the commands that we've covered

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in this video and all the other commands that we're going to cover in this section of the course at

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the conclusion lecture of this section.

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But the use case of these commands that we've covered in this lecture may not be completely clear at

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this point, and that's okay.

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I wasn't trying to teach you all like a whole bunch of commands in one video.

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What I wanted to get across in this video is that commands are executed by typing some weird text in

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the terminal and pressing the enter key.

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You've also seen that commands can be they can do a whole lot of different things and they can also

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be customized for different behavior.

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But they all seem to follow a semi similar kind of structure.

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You type some text, maybe you've got some options, maybe you've got some input and you press enter.

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Now being able to understand that structure is of incredible importance to mastering the Linux operating

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system and leveraging the power of the terminal.

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So in the next video, I'm going to show you how commands are structured in Linux and what we're going

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to cover next will serve as a critical foundation for pretty much everything that we're going to learn

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going forward and pretty much everything that you will ever learn when you're using Linux.

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If you've used Linux before, but never really felt as though you've, you know, you got it or you

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felt that some stuff was missing.

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In your understanding, it's probably because you weren't shown what I'm about to show you next.

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And if you're new to Linux, this is going to be the best place to start to make sure that everything

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goes smoothly and you start to see the pattern of how the Linux operating system and the commands are

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designed rather than just memorizing a massive list.

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So for that super important stuff, I'll see you in the next video.